This assembly consists of a vertical fin roll made in 3 parts and a vertical bottom support roll. This has arrangement of rotating & up/ down adjustment.
The only function of the seam guide is to prevent the seam from rolling under the edge of the squeeze rolls. If the mill is set well enough so that this does not happen, then no seam guide is needed. Admittedly this is unusual. In general it is recommended that a seam guide be used.